Biology

Photosynthesis in Plants

1,492 Questions

Photosynthesis is the biological process by which plants convert light energy into chemical energy. This page contains practice questions covering essential topics like chlorophyll, light reactions, and the pathways specific to plants. This material is crucial for medical entrance exams and academic assessments.

Chlorophyll and pigmentsLight reactionsCalvin cycleCAM plantsElectron transportPhotosynthesis factors

Photosynthesis in Plants Questions

Multiple choice

Which cycle occurs in sugarcane?

  1. Hatch slack

  2. Calvin cycle

  3. Photorespiration

  4. C2 cycle
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

It is a C4 plant. Hence, it follows the 'hatch slack' pathway.

Multiple choice

Photorespiration is favoured by

  1. high oxygen and low carbon dioxide

  2. low temperature

  3. low light intensity

  4. low oxygen and high carbon dioxide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

High concentration of oxygen and low carbon dioxide favour photorespiration.

Multiple choice

What do green plants release during night?

  1. Oxygen

  2. Carbon dioxide

  3. Carbon monoxide

  4. Nitrogen dioxide

  5. Ozone
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carbon dioxide is a by-product of respiration, which is carried out by all organisms all the time, even at night.

Multiple choice

When are the carbohydrates formed in the plants?

  1. During respiration

  2. During night

  3. During water absorption by roots

  4. During photosynthesis

  5. During transpiration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The carbohydrates are formed in the plants during photosynthesis.

Multiple choice

Which of the following statements are correct about C4 plants?

A. CO2 fixation occurs twice. B. PEP acts as CO2 acceptor in bundle sheath. C. Leaf anatomy is of Kranz type. D. They require 18 ATP for synthesis of one molecule of glucose.

  1. A and B

  2. A and C

  3. B and C

  4. B and D

  5. C and D
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct because in C4 plants, CO2 fixation occurs twice, once in mesophyll cells to form oxaloacetic acid and another in bundle sheath cells to form 3-phosphoglyceric acid. Kranz-type leaf anatomy is found in C4 plants.

Multiple choice

Which of the following statements are incorrect about photo system I?

A. PS I lies in outer surface of thylakoids. B. Reaction centre of PS I is P680. C. It participates in both cyclic as well as non-cyclic phosphorylation. D. Molecular oxygen is evolved as a result of photolysis of water.

  1. A and B

  2. A and C

  3. A and D

  4. B and C

  5. B and D
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This option is correct because reaction centre of PS I is P700 and molecular oxygen is not evolved in PS I. It is evolved as a result of photolysis of water in PS II.

Multiple choice

Which of the following statements are incorrect about photosynthesis?

  1. Best photosynthesis takes place in green light.
  2. Quantum yield of photosynthesis is 0.125.
  3. Energy conversion efficiency of photosynthesis is 66%.
  4. 90% of the total photosynthesis in the world is carried out by marine algae.

  1. 1 and 2

  2. 1 and 3

  3. 1 and 4

  4. 2 and 3

  5. 3 and 4
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct because energy conversion efficiency of photosynthesis is 33% and best photosynthesis takes place in red light, next best in blue light and nil in green light.

Multiple choice

Which of the following statements are correct about non-cyclic phosphorylation?

  1. It is an oxygenic process.
  2. Only one light trapping system (PS I) is involved.
  3. No NADPH is synthesised.
  4. NADP acts as last electron acceptor.

  1. 1 and 2

  2. 1 and 3

  3. 2 and 3

  4. 1 and 4

  5. 3 and 4
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This option is wrong because non-cylic phosphorylation is an oxygenic process, i.e. oxygen is given off during the process and NADP acts as last electron acceptor in non-cyclic phosphorylation.